OpenVSA

VSA, or Virtual System Architecture is a low-level software library included in the bootloader/BIOS for system using AMD Geode-series CPUs and companion chips.

AMD released VSA sources under the name geode-vsa in 2006 (licensed under the terms of the GNU LGPL). Those sources were hosted by the OLPC project, and can be pulled with git from git://dev.laptop.org/geode-vsa. The OpenVSA sources include modified geode-vsa sources, as well as some new components also released under the GNU LGPL.

The VSA code runs under x86 SMM (System Management Mode) which is like "real mode" with some extra opcodes, priviledges, and side-effects.

As originally published, the VSA code compiled and assembled with older, commercially unavailable versions of Microsoft tools. The OpenVSA code has been modified in order to build under a GNU toolchain so that it may be maintained and enhanced by a wider group of users.